Recently, I saw this kind or error quite frequent. At first I thought that it was nothing.
But eventually, it’s kinda bothering me when I see the error message. :p
So, here is the solution to solve this problem.
First, run this command:
It updates /etc/default/locale with provided values.
If you see the /etc/default/locale file, it shows something like this:
If the problem still occur, maybe you can try this first before running the command above again: